KR20210083254A - A system and method for generating, at a transmitter, a stream of symbol frames configured for efficient processing at a receiver - Google Patents

Abstract

A system and method for generating frames composed of blocks is disclosed, wherein each block includes data symbols corresponding to a higher order orthogonal modulation format and support symbols corresponding to a lower order modulation format. One or more of the blocks may further include markers comprising distinct symbol patterns. The markers may mark the beginning of each frame and/or another location within the frame. Support symbols may be in a common location within each block.

Description

A system and method for generating, at a transmitter, a stream of symbol frames configured for efficient processing at a receiver

This application claims priority from US Patent Application Serial No. 16/132325, filed on September 14, 2019, which is incorporated herein in its entirety.

The demand for high-throughput data transmission is always increasing. For example, there is a growing need in the industry to transmit larger and larger amounts of data at increasingly faster rates. This has created a need to improve the efficiency of processing at both the transmitter and receiver. Embodiments of the present invention organize symbols representing multiple bits into parallel symbol blocks, which form frames for transmission to a receiver. The properties of frames provide processing advantages.

1 illustrates an example of a telecommunication transmitter in accordance with some embodiments of the present invention.
2 illustrates an example of streams of frames each comprising symbol blocks in accordance with some embodiments of the present invention.
3 shows an example of a framer in accordance with some embodiments of the present invention.
4 illustrates an example of how a framer may operate in accordance with some embodiments of the present invention.
5A-5D show examples related to the method of FIG. 4 in accordance with some embodiments of the present invention.

This specification describes exemplary embodiments and applications of various embodiments of the present invention. However, the present invention is not limited to the exemplary embodiments and applications or the manner in which the exemplary embodiments and applications operate or described herein. Moreover, the drawings may show simplified or partial views, and dimensions of elements in the drawings may be exaggerated or not to scale for clarity. Moreover, as the terms “on,” “attached to,” or “coupled to” are used herein, an object (eg, material, layer, substrate) etc.) means that an object is "attached" to, "on" another object, regardless of whether one object is directly on, attached to, or coupled to, or whether there are one or more intervening objects between one object and the other ", or "coupled". Also, directions (eg, above, below, top, bottom, side, up, down, under, over) (over, upper, lower, horizontal, vertical, “x”, “y”, “z”, etc.), where provided, are relative and by way of example and illustration only. and for ease of discussion and not by way of limitation. Moreover, when a reference is made to a list of elements (eg, elements a, b, c), such reference per se refers to any one of the listed elements, any combination of less than all of the listed elements, and and/or combinations of all listed elements are intended to be included.

As used herein, “substantially” means sufficient to operate for its intended purpose. When used in reference to a numerical value or range, it means substantially within 10 percent. The term “ones” means more than one.

1 illustrates an example of a communications transmitter 100 for mapping user bits into orthogonally modulated symbols, organizing the symbols into frames comprising symbol blocks, and transmitting the frames to a telecommunication receiver (not shown). do. Although not shown, the transmitter 100 includes digital signal processing (DSP) circuitry, digital-to-analog converters (DACs), and supporting analog circuitry (eg, for example, amplifiers, multiplexers, couplers, etc.). Frames cleanly organize the symbols to facilitate fast and efficient processing at both the transmitter 100 and the receiver (not shown).

As shown, the communication or client information (eg, message, file, multi-media object, web page, etc.) 170 to be transmitted to a remote receiver (not shown) is for transmission to a remote receiver (not shown). It is processed to produce digital data in the form of bits 110 (generally represented by pre-processing 102 ). Bits 110 are sometimes referred to herein as user bits or client bits. Preprocessing 102 may include functions such as encoding (eg, source encoding and channel), encryption, and/or the like. In some embodiments, preprocessing 102 receives bits in its input and removes it in addition to or in addition to client information 170 .

Framer 120 may map bits 110 to symbols and organize the symbols into frames each containing blocks of multiple symbols. Thus, framer 120 preprocesses 102 to generate so-called “waveform frames,” which may be actual frames of symbols to be transmitted over a communication medium (not shown) to a receiver (not shown). It may be understood as a module of the transmitter 100 that performs bit parsing, bit-to-symbol mapping, and/or symbol reformatting using bits output by the . Accordingly, the framer 120 may be a waveform framer.

As shown, framer 120 may generate streams 112 and 113 of multiple frames (sometimes referred to herein as “frame streams”) from bits 110 . In the example illustrated in FIG. 1 , framer 120 generates a first frame stream 112 and a second frame stream 113 . Each of the frame streams 112 and 113 may be subjected to additional digital and analog processing 130 , wherein the first frame stream 112 is modulated onto the first carrier signal 122 and the second frame stream 113 is modulated onto the first carrier signal 122 . may result in being modulated onto this second carrier signal 124 . The combiner 140 may combine the carrier signals 122 and 124 into a composite signal 132, which may be coupled to the transmit module 150 over a channel or communication medium (not shown) for transmission to a receiver (not shown). can be launched by

The composite signal 132 may be a communication signal. For example, composite signal 132 may be a baseband communication signal or any type of signal including a modulated optical signal or any other type of modulated electromagnetic signal, whether transmitted wirelessly or over a physical medium such as optical fiber, cable, or the like. It may be a bandpass communication signal of For example, composite signal 132 may be a dual-polarization optical signal in which carrier signals 122 and 124 may be mutually orthogonal optical signals. For example, the first carrier signal 122 may be a horizontally polarized optical signal, and the second carrier signal 124 may be a vertically polarized optical signal. The transmit module 150 may be a module including various transmitter front-end elements, eg, amplifiers, multiplexers, fiber pigtails, couplers, antennas, etc., which transmit the composite signal 132 . It can be combined or launched as a channel or communication medium for

Framer 120 may map bits 110 to orthogonal symbols. As is known, a quadrature symbol includes an in-phase component and a quadrature component. As is also known, the I and Q component pairs for each symbol may be carried on separate signals (not shown). Accordingly, the first stream 112 may include two signals (not shown): one signal carrying the I components of the symbols (not shown), and another signal carrying the corresponding Q components. (not shown). Similarly, the second stream 113 also includes I and Q signals (not shown). However, for ease of illustration and discussion, while the descriptions herein are made with reference to symbols, each symbol may include a 1/Q component pair and any signal or stream of symbols may contain one of the I components of the symbols. It should be understood that it may include two signals or streams, one carrying and the other carrying the corresponding Q components of the symbols. Thus, any stream of symbols, although shown or discussed herein in terms of a single symbol entity, whether a stream of individual symbols, a stream of symbol blocks, or a stream of frames, is a stream or signal Two streams or signals may contain I components and the other stream or signal contains Q components. In general, each symbol may include any number of predetermined components (or dimensions). For example, symbols associated with multi-dimensional modulation formats, whose number of dimensions is greater than two, will have as many components as the number of dimensions of the base modulation format. As an example, a two-dimensional modulation format may be defined in a two-dimensional space spanned by orthogonal signals (eg, I and Q), but an additional dimension to the three-dimensional modulation format I and Q, eg, time , can be defined over the three-dimensional space spanned by the space. However, without loss of generality, symbols are described herein as multi-component (or multi-dimensional) symbols having two components (or dimensions), I and Q.

Many different quadrature decoding formats are known, including phase shift keying (PSK) and quadrature amplitude modulation (QAM) formats. Examples of orthogonal modulation formats include QPSK, 8-PSK, 8-QAM, 16-PSK, 16-QAM, 32-QAM, 64-QAM, 128-QAM, 256-QAM, and the like. The foregoing or other known or later developed orthogonal modulation formats may be used in embodiments of the present invention. As is known, the "order" of an orthogonal modulation format corresponds to the number of different symbols in the format's symbol constellation. The fewer the number of symbols in the constellation, the lower the order, and the greater the number of symbols in the constellation, the higher the order. Also, the larger the order, the greater the number of bits 110 each symbol represents.

The transmitter 100 , and thus its DSP circuitry (not shown), and thus a framer 120 configured by the DSP, has several predetermined operating modes identified by the operating mode identifier signal 114 . can support them As used herein, the term “supported operating modes” refers to the DSP of the transmitter, including the framer 120 , and thus the framer 120 system itself, several of which may be configured to operate. Predetermined modes of operation are described. Similarly, "selected operating mode" is used herein to describe a selected one of the supported operating modes. Each one of the supported modes of operation includes a first plurality of modulation formats and a second plurality of modulation formats to be used in generating different types of symbols from bits 110 , as described in greater detail herein. is associated with The term “supported modulation format(s)” is understood herein to refer to a superset of modulation format(s) associated with the supported modes of operation. The term “selected modulation format(s)” is understood herein to correspond to the modulation format(s) associated with the selected mode of operation as identified by signal 114 .

Framer 120 may be configured to map some of bits 110 to any of several supported modulation formats associated with the selected mode of operation as identified by signal 114 . For example, in some embodiments, framer 120 maps some bits 110 to selected first and second plurality of modulation formats associated with the mode of operation as identified by signal 114 . can do it However, without loss of generality and for brevity of discussion, each mode of operation is described herein as being associated with a first modulation format and a second modulation format. Moreover, the second modulation format is described herein as being the same for all supported modes of operation. For example, the selected first modulation format and the second modulation format may each be any of the QAM formats listed above. For example, the second modulation format may be of a lower order than each of the supported first modulation formats. The second modulation format may be, for example, QPSK, while each of the supported first modulation formats may be any of the QAM formats having an order greater than QPSK.

2 illustrates an example of a frame stream 200 that may be generated by a framer 120 . Frame stream 112 and/or second frame stream 113 of FIG. 1 may be similar to frame stream 200 .

As shown, the frame stream 200 may include frames 202 , each of which may include a fixed number of Y symbol blocks 210 . Each symbol block 210 may include a fixed number of N symbols (which may facilitate parallel processing at the transmitter 100 and/or the receiver (not shown)). The numbers Y and N may be constant for all supported modes of operation.

As mentioned, an orthogonally modulated symbol comprises a 1/Q component pair. Thus, stream 200 may include two similar streams of frames (not shown): one carrying the I components of each symbol, and the other carrying the corresponding Q components of each symbol. However, for ease and simplicity of discussion, stream 200 is illustrated as a single stream carrying symbols, however, it should be understood that each symbol includes an I and Q component.

As shown, each symbol block 210 may include data symbols 232 , support symbols 230 , marker symbols SOF 220 and MRK 224 , and padding 234 . . Data symbols 232 may correspond to bits 110 mapped according to a selected first modulation format, and support symbols 230 may correspond to other ones of bits 110 mapped according to a second modulation format. can respond.

As shown, the support symbols 230 may be at approximately the same location in all blocks 210 within the frame 202 . For example, the exact starting index of the support symbols 230 for the start of each block 210 that includes the support symbols 230 , and the number of support symbols 230 may be predetermined and the selected operation It may vary depending on the mode. Similarly, the exact starting index of the data symbols 232 for the start of each block 210 containing the data symbols 232 , and the number of data symbols 232 may be predetermined and selected for the selected mode of operation. may vary according to

Moreover, one or more of blocks 210 within frame 202, eg, SOF 220 and MRK 224, may include special markers comprising distinct patterns of symbols. It is noted that what is sometimes referred to in the industry as a unique word is an example of such a special marker. The symbols of the special markers may correspond to a second modulation format or a modulation format different from both the first modulation format and the second modulation format. The symbols of the special marker typically do not correspond to any of the bits 110 .

In the example shown in FIG. 1 , the first block 210 and the Xth block 210 in the frame 202 include such special markers. For example, the first block 210 may include a start-of-frame SOF 220 symbol pattern that marks the beginning of each frame 202 . The Xth block 210 of the frame 202 may include a middle marker MRK 224 symbol pattern, which may include any markings at a particular location (eg, approximately in the middle) of the frame 202 . serve a number of purposes. The SOFs 220 in all frames 202 in stream 200 may be the same, and the MRKs 224 may likewise be the same in all frames 202 in stream 200 . However, the SOFs 220 and MRKs 224 may be different. If the framer 120 produces more than one frame stream, such as the first frame stream 112 and the second frame stream 113 shown in FIG. 1 , the SOFs in one stream (eg, 112 ) ( 220 ) and MRKs 224 may be different from SOFs and MRKs in another stream (eg, 113 ). Moreover, as mentioned, the first frame stream 112 may be decomposed into a first frame stream I (not shown) and a first frame stream Q (not shown), which are respectively first frame stream 112 . Carry the I and Q components of each symbol of Similarly, the second frame stream 113 may be decomposed into a second frame stream I (not shown) and a second frame stream Q (not shown). In such cases, the SOFs 220 and MRKs 224 in each component stream (eg, I stream of 112, Q stream of 112, I stream of 113 and Q stream of 113) are different from each other. can Each mode of operation may be associated with a distinct set of symbol patterns of SOFs 220 and MRKs 224 . For example, the start indexes of the SOFs 220 and MRKs 224 may be the same regardless of the selected mode of operation. For example, SOFs 220 and MRKs 224 may have a start index of one as they are located at the start of each block in which they are included. As another example, and as also noted above, the location of the SOFs 220 and MRKs 224 within each frame 202 may be the same regardless of the selected mode of operation. However, the number of symbols included in the SOFs 220 and MRKs 224 associated with a given mode of operation depends on that mode of operation. That is, SOFs 220 and MRKs 224 may have different numbers of symbols in one supported mode of operation compared to another.

As shown, the final (Y-th) block 210 may include padding 234 (eg, padded symbols) as required to complete the Y-th block 210 . For each supported mode of operation, the number of bits 110 that can be carried by each frame 202 is a predetermined fixed value. For example, a predetermined number of bits 110 to be carried in each frame 202 for a given mode of operation may be fitted to the frame 202 by forward error correction (FEC) codewords. (codewords) can be determined based on the number. As also mentioned, bits 110 are mapped to data symbols 232 based on a selected first modulation format and others of bits 110 are supported symbols 230 based on a second modulation format. is mapped to For the selected mode of operation as identified by signal 114 , all associated predetermined numbers of bits 110 to be carried in each frame 202 are associated with an associated predetermined number of data symbols 232 and a support symbol. If it cannot be mapped to the associated predetermined number of bits 230, then some bits 110 will be left unmapped. Also, due to such inconsistency, the last block (Yth) 210 of each frame 202 may have some positions left unfilled. Both the number of bits to be left unmapped and the number of padding bits needed to fill unfilled positions in the last block 210 of each frame 202 may also be predetermined for each supported mode of operation. Accordingly, the unmapped bits may be first padded with a predetermined number of padding bits, eg, randomly generated bits or bits extracted from a known sequence, and then the resulting set of bits is selected It may be mapped to data symbols based on the first modulation format and stored in the padding 234 of the final block (Y-th) 210 .

The SOF 220 may include a distinct pattern of symbols that may be easily detected at a receiver (not shown), for example, via correlations. Accordingly, the SOF 220 is designed to have desirable auto- and cross-correlation properties to facilitate determining the boundaries of frames at a receiver (not shown). In some embodiments, the receiver receives (including SOF 220 ) before initiating its search for frame boundaries to increase the resilience of the frame boundary search process to various obstacles and/or distortions. Differential decoding may be performed on the sampled samples. For example, during signal acquisition, a frequency offset present in the signal may prevent access to absolute phase information. Since differential encoding associates transmitted bits with phase transitions rather than absolute phases, those bits can be recovered via differential decoding at the receiver without the absolute phases having to be determined. In such embodiments, SOF 220 may be designed to have desirable auto- and cross-correlation properties when used with or without differential decoding. Using differentially decoded SOFs, the receiver can thus allow the receiver (not shown) to identify the start of a frame in the received samples even when the transmitted signal is subjected to various disturbances and/or distortions.

3 illustrates an exemplary configuration (labeled 300 in FIG. 3 ) of framer 120 . For ease of explanation, FIG. 3 is discussed as generating frames corresponding to frames 202 illustrated in FIG. 2 . However, the framer 300 is not so limited.

As can be seen, the framer 300 may generate each block 210 of the frames 202 shown in FIG. 2 from the bits 110 . For example, each of the first through Y-th blocks 210 of the frame 202 may be generated from the framer output 380 . For example, the symbols of the SOF 220 or MRK 224 (if present) and the data symbols 232a of the first group of each block 210 are output by the symbol generator 304 to the framer output ( A first region 382 of 380 may be provided, and the supporting symbols 230 of each block 210 are provided by a symbol generator 304 to a second region 384 of a framer output 380 . The data symbols 232b and padding 234 (if present) of the second group of each block 210 are generated by the symbol generator 304 in the third region 386 of the framer output 380 . ) can be provided. As each block 210 is generated, it can be output from a framer output 380 , producing the frame stream 200 illustrated in FIG. 2 .

In the example shown in FIG. 3 , framer 300 includes controller 310 , framer input 330 , marker module 340 , data symbol mapper 350 , support symbol mapper 360 , padding module 370 , and a framer output 380 .

The controller 310 may control the operation of the framer 300 . As shown, the controller 310 may include a tracker 312 , which may track the index of the current block 210 within the frame 202 being generated. As also shown, the controller 310 receives an operation mode identifier signal 114 and based on the signal 114 a number of symbols in each block 210 of each frame 202 to be generated in the selected mode of operation. It is possible to determine the associated predetermined sizes and positions of each type. The controller 310 generates a current block 210 in the framer output 380 according to the selected first modulation format as indicated by the signal 114 and the current block index as tracked by the tracker 312 . control signals 316 may be issued to other elements of the framer 300 for

Framer input 330 receives bits 110 and sets sets of bits 110 according to control signals 316 , input 352 of data symbol mapper 350 , input of support symbol mapper 360 . 362 , and/or input 388 of padding module 370 . In some embodiments, framer input 330 may include a buffer for buffering bits 110 .

Data symbol mapper 350 may map bits 110 provided at its input 352 to data symbols according to a selected first modulation format as indicated by signal 114 . An output 354 of the data symbol mapper 350 may optionally provide data symbols to a first region 382 and/or a third region 386 of the framer output 380 . Control signals 316 may control which and how many bits 110 are provided to data symbol mapper 350 from framer input 330 . Control signals 316 may further control positions within first region 382 and/or third region 386 of framer output 380 from which data symbols are provided.

Support symbol mapper 360 may map bits 110 provided at its input 362 to support symbols according to a second modulation format. The output 364 of the support symbol mapper 360 may optionally provide the support symbols to the second region 384 of the framer output 380 . Control signals 316 may control which and how many bits 110 from framer input 330 are provided to support symbol mapper 360 .

The marker module 340 can optionally provide the symbols of the SOF 220 and/or the MRK 224 to the first region 382 in the framer output 380 via its output 344 . The marker module 340 is configured among a number of different SOFs 220 and/or MRKs 224 based on the control signals 316 determined based on the selected mode of operation as indicated by the signal 114 . A selected one may be provided. For example, as noted, each selectable SOF 220 may include a different pattern of symbols. Similarly, as noted, each selectable MRK 224 may include a different pattern of symbols. The control signals 316 may select a particular one of the available SOFs 220 and/or MRKs 224 to provide to the first region 382 . The control signals 316 may also control the position within the framer output 380 , at which the selected SOF 220 or MRK 224 is provided, and the thus generated symbol block 210 .

The padding module 370 may optionally provide padding 234 of the padded symbols to a third region 386 within the framer output 380 via its output 374 , as previously described. . The control signals 316 may control the position within the framer output 380 at which the padding 234 is provided, and thus the position within the resulting symbol block 210 .

Framer output 380 includes outputs 344, 354, 364, and 374 from marker module 340, data symbol mapper 350, support symbol mapper 360, and padding module 370, respectively, as discussed above. ) can be received. As mentioned, this output may include a newly constructed block 210 . Then, the framer output 380 may output the newly constructed block 210 . The controller 310 may control the frame output 380 with the control signals 316 . In some embodiments, framer output 380 may include a buffer.

4 shows an example of a method 400 for constructing a stream of frames from user bits in accordance with some embodiments of the present invention. For ease of discussion, method 400 is discussed below with respect to a framer 300 as shown in FIG. 3 , which operates to generate the example frame stream 200 shown in FIG. 2 , but method 400 . is not so limited.

For simplicity of explanation, the method 400 of FIG. 4 is shown and described as executing serially, however, the present invention provides that some aspects may occur in different orders and/or concurrently with other aspects from those shown and described herein. Also, it is not limited to the illustrated order. For example, 412-416 may be performed substantially simultaneously. Acts 432-438 may similarly be performed substantially concurrently, such as 452-458 and/or 472-478.

As mentioned, the controller 310 may include a tracker 312 that tracks the currently configured block 210 . In the following description of the method 400 , it is assumed that the tracker 312 maintains an index that identifies the location of the current block 210 within its frame 202 . The index is merely an example, and the current block 210 may be tracked in other ways.

At 404 , the process branches to create the type of current block to be created. When the block index points to the first block 210 (eg, as maintained by the tracker 312 of the controller 310 ), the method 400 branches from 404 to 430 .

At 430 , the controller 310 controls the framer 300 to generate the first block 210 in the frame 202 . Acts 432-438 illustrate an example.

At 432 , the marker module 340 may provide the selected SOF 220 symbol pattern to the selected location within the first region 382 of the framer output 380 . The size (eg, in symbols) of SOF 220 may vary according to signal 114 . Accordingly, the controller 310 may provide the control signals 316 that cause the marker module 340 to provide the desired SOF 220 to a desired location within the first area 382 of the framer output 380 . An example of the SOF 220 symbol pattern 502 provided to the first area 382 from the marker module 340 is shown in FIG. 5A .

At 434 , a sufficient number of bits 110 to map to data symbols to fill the remaining symbol positions in first region 382 are provided from frame input 330 to data symbol mapper 350 . The data symbol mapper 350 maps the bits 110 to data symbols and provides the data symbols to the remaining locations within the first region 382 .

The number of bits 110 provided to data symbol mapper 350 at 434 may depend on signal 114 . For example, the number of bits per data symbol, the number of symbols provided in the first region 382 , and the number of symbols in the SOF 220 provided at 432 may depend on the signal 114 . The controller 310 may determine the number of bits 110 provided from the signal 114 to the data symbol mapper 350 and locations within the first region 328 for the resulting data symbols. The controller 310 may provide the control signals 316 in accordance with the determinations described above. An example of data symbols 504 provided from data symbol mapper 350 to first region 382 is shown in FIG. 5A .

At 436 , a sufficient number of bits 110 to map to support symbols for the second region 384 of the framer output 380 are provided from the frame input 330 to the support symbol mapper 360 , which The resulting support symbols are provided to the second area 384 .

The number of support symbols to be provided in the second region 384 may depend on the signal 114 . The controller 310 may determine from the signal 114 the number of bits 110 to provide to the support symbol mapper 360 and positions within the second region 384 for the resulting support symbols. As mentioned, in some embodiments, the second modulation format of the supported symbols may be fixed and thus not dependent on the signal 114 . The controller 310 may provide the control signals 316 in accordance with the determinations described above. An example of the support symbols 506 provided from the support symbol mapper 360 to the second region 384 is shown in FIG. 5A .

At 438 , a sufficient number of bits 110 to map to data symbols for a third region 386 are provided from frame input 330 to data symbol mapper 350 , which maps the resulting data symbols to a third region 386 .

As noted, the size (eg, in number of symbols) of the third region 386 may depend on the signal 114 . The controller 310 may determine from the state of the signal 114 the number of bits 110 to provide to the data symbol mapper 360 and positions within the third region 328 for the resulting data symbols. The controller 310 may provide the control signals 316 in accordance with the determinations described above. An example of data symbols 508 provided from data symbol mapper 350 to third region 386 is shown in FIG. 5A .

At 484, the block index may be incremented. At 488 , the first symbol block 210 generated in the frame output 380 may be output on the stream 200 . The method 400 may then return to 404 . At step 404 , this time the block index points to the second block 210 , and the method 400 branches to 410 .

At 410 , the controller 310 controls the framer 300 to generate a regular block (the second block 210 ). Acts 412 - 416 illustrate an example of creating a regular block, such as the second block 210 .

At 412 , a sufficient number of bits 110 to map to data symbols for a first region 382 are provided from frame input 330 to data symbol mapper 350 , which maps the resulting data symbols to a first region 382 . Act 412 may be similar to 438 . For example, the number of symbols to be provided to the first region 382 as well as the number of bits per data symbol may depend on the signal 114 . The controller 310 may determine the number of pits 110 to provide to the data symbol mapper 350 from the foregoing. The controller 310 may provide the control signals 316 as described above. An example of data symbols 514 provided from data symbol mapper 350 to first region 382 is shown in FIG. 5B .

At 414 , a sufficient number of bits 110 to map to the support symbols for the second region 384 are provided from the frame input 330 to the support symbol mapper 350 , which converts the resulting support symbols to the second region 384 . area 384 is provided. Act 414 may be generally performed in a manner similar to 436 . An example of the support symbols 516 supported from the support symbol mapper 360 to the second region 384 is shown in FIG. 5B .

At 416 , a sufficient number of bits 110 to map to data symbols for a third region 386 are provided from the frame input 330 to a data symbol mapper 360 , which maps the resulting data symbols to a third region 386 . Act 416 may be generally performed in a manner similar to 438 . An example of data symbols 518 supported from data symbol mapper 360 to third region 386 is shown in FIG. 5B .

At 484, the block index may be incremented. At 488 , the second symbol block 210 generated in the frame output 380 may be output on the stream 200 . Acts 404 , 412 - 16 , 484 , and 488 are to be repeated to create each block 210 and output it as stream 200 from the third block to the (X-1)th block 210 . can After generating the (X−1)th block 210 , the block index is incremented from 484 to the (X)th block 210 , and at 404 , the method 400 branches to 450 . At 450 , the controller 310 controls the framer 300 to generate the X-th block 210 . Acts 452-458 illustrate an example of creating the X-th block 210 . As illustrated, the X-th block 210 may be similar to the first block 210 .

Actions 452-458 may be performed in a similar manner to 432-438 except that MRK 224 is provided by marker module 340 instead of SOF 220 . MRK 224 symbol pattern 522 and data symbols 524 provided to first area 382 from marker module 340 and data symbol mapper 350, and second area from support symbol mapper 360 ( Examples of support symbols 526 provided to 384 , and data symbols 528 provided from data symbol mapper 350 to third region 386 are shown in FIG. 5C .

At 484 , the block index may be incremented, and at 488 , the Xth symbol block 210 generated in frame output 380 may be output onto stream 200 . Then, acts 404, 412-16, 484, and 488 create each block 210 from the (X+1)-th block to the (Y-1)-th block 210 and convert it to stream 200 ) can be repeated to output After generating the (Y-1)th block 210, the block index is incremented from 484 to the (Y)th block 210, and at 404, the method 400 branches to 470, where the controller 310 controls the framer 300 to generate the Y-th block 210 . Acts 472-478 illustrate an example of creating a block similar to the Y-th block 210 .

At 472 , a sufficient number of bits 110 to map to data symbols for a first region 382 are provided from frame input 330 to data symbol mapper 360 , which maps the resulting data symbols to a first region 382 . Act 472 may be generally performed in a similar manner to 412 . An example of data symbols 534 provided from data symbol mapper 350 to first region 382 is illustrated in FIG. 5D .

At 474 , a sufficient number of bits 110 to map to support symbols for the second region 384 are provided from the frame input 330 to a support symbol mapper 360 , which converts the resulting support symbols to a second area 384 is provided. Act 474 may be generally performed in a manner similar to 436 . An example of the support symbols 536 provided from the support symbol mapper 360 to the second region 384 is illustrated in FIG. 5D .

At 476 , a sufficient number of bits 110 to map to data symbols for the third region 386 are provided from the frame input 330 to the data symbol mapper 350 . The symbol mapper 350 maps the bits 110 to data symbols and provides the data symbols to corresponding locations within the third region 386 .

As mentioned, the number of symbols to be provided in the third region 386 of the Y-th block as well as the number of bits per data symbol and the number of symbol positions to be occupied by the data symbols depend on the signal 114 . The controller 310 can determine the number of bits 110 to provide to the data symbol mapper 350 from the foregoing and the locations within the third region 386 for the resulting data symbols. The controller 310 may provide the control signals 316 in accordance with the determinations described above. An example of data symbols 538 to be provided from the data symbol mapper 350 to the third region 386 is shown in FIG. 5D .

At 478 , the padding module 370 may provide padding to the third region 386 as discussed above. The controller 310 can determine the size of the padding 234 from the signal 114 . The controller 310 may provide the control signals 316 as described above. An example of the padding 540 provided from the padding module 370 to the third region 386 is shown in FIG. 5D .

At 480, the block index may be reset. At 488 , the Yth symbol block 210 generated in frame output 380 is output onto stream 200 . The method 400 has now generated one of the example frames 202 shown in FIG. 2 . The method 400 may then return to 404 to continue generating frames 202 . The frames 202 including the blocks 210 output at 488 may be output for transmission by the transmission module 150 of FIG. 1 to a remote transmitter (not shown).

In some embodiments, block 210 may be generated substantially simultaneously at framer output 380 . For example, 412-416 may be performed substantially simultaneously to produce a regular block at framer output 380 . Similarly, 432-438 may be performed substantially concurrently to generate the first block 210 in the framer output 380, and 452-458 may be performed substantially concurrently to generate the X-th block 210 in the framer output 380. can be performed substantially simultaneously. Likewise, steps 472 - 478 may be performed substantially simultaneously to produce the Y-th block 210 at the framer output 380 . Alternatively, some or all of the acts described above may be performed continuously.

As mentioned, frame stream 200 may be an example of frame stream 112 and/or frame stream 113 of FIG. 1 . In some embodiments, multiple instantiations of framer 300 may generate multiple frame streams (eg, 112 and 113 ) from multiple groups of bits 110 . For example, frame stream 200 may be generated from first bits (eg, 110 ), resulting in frame stream 112 , and second frame stream 200 includes second bits (eg, 110 ). not, but may be similar to bits 110 ), resulting in a frame stream 113 . In other embodiments, the framer 300 of FIG. 3 may be modified to generate multiple frame streams similar to 200. For example, a divider (not shown) splits the symbols output by data symbol mapper 350 and, for example, between two framer outputs (not shown but each may be similar to 380). (360) can be supported.

The blocks 210 and frames 202 illustrated in FIG. 2 are merely examples. In other embodiments, other examples of blocks and frames may be created. For example, 410 of FIG. 4 may be an example of generating a block containing both data symbols and support symbols; 430 and 450 may be examples of generating a block containing both data symbols and support symbols and a marker pattern of symbols; 470 may be an example of generating a block that includes both data and support symbols and padding.

The elements of FIG. 1 or FIG. 3 may be implemented in software, hardware (eg, digital logic and/or analog circuits), and/or a combination of the foregoing. Any such software may reside, for example, in a digital memory (not shown) where it is executed by the controller 310 . Alternatively, one or more of the elements of FIG. 1 or FIG. 3 may include a processor (not shown) for executing software from a memory (not shown).

The controller 310 may be a separate module as illustrated in FIG. 3 , whether configured as software, hardware, or a combination of hardware and software. Alternatively, the controller 310 may be distributed among any one or more of the other modules illustrated in FIG. 3 . The method 400 illustrated by FIG. 4 may be implemented in any such configuration of software and/or hardware as discussed above.

Although specific embodiments and applications have been described herein, these embodiments and applications are exemplary only, and many variations are possible. In addition to any previously indicated modifications, many other modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of this description, and the appended claims are intended to cover such modifications and arrangements. do. Accordingly, while the information has been described above with particularity and detail in connection with what is presently considered to be its most substantial and preferred aspects, numerous modifications, including but not limited to form, function, mode of operation and use, are subject to the principles set forth herein. It will be apparent to one skilled in the art that this may be done without departing from the concepts and concepts. Also, as used herein, examples are meant to be illustrative only and should not be construed as limiting in any way.

Claims (24)

A method for generating, in a communication transmitter, a stream of symbol blocks each comprising a first region and a second region, the method comprising:
a data symbol comprising a first set of user bits modulated according to a first orthogonal modulation format and a distinct symbol pattern identifying a start of a frame of said symbol blocks in said first region of a first one of said symbol blocks providing a first set of
providing a first set of support symbols comprising the second set of user bits modulated according to a second orthogonal modulation format in the second region of the first one of the symbol blocks;
providing a second set of data symbols comprising the third set of user bits modulated according to the first orthogonal modulation format in the first region of the second one of the symbol blocks;
providing the second set of support symbols including the fourth set of user bits modulated according to the second orthogonal modulation format in the second region of the second one of the symbol blocks; and
outputting the first one of the symbol blocks and the second one of the symbol blocks for transmission to a remote receiver;
wherein the first orthogonal modulation format is of a higher order than the second orthogonal modulation format. According to claim 1,
A pattern for identifying a middle marker of the frame of the symbol blocks modulated according to the second orthogonal modulation format in the first region of an X-th symbol block among the symbol blocks and the modulated according to the first orthogonal modulation format and providing a third set of data symbols comprising a fifth set of user bits. 3. The method of claim 2,
providing the third set of support symbols including the sixth set of user bits modulated according to the second orthogonal modulation format in the second region of the Xth symbol block of the symbol blocks How to. 4. The method of claim 3,
and the Xth one of the symbol blocks corresponds to approximately the middle of the frame. According to claim 1,
providing a third set of data symbols comprising the fifth set of user bits modulated according to the first orthogonal modulation format in the first region of a last one of the symbol blocks of the frame;
providing the third set of support symbols including the sixth set of user bits modulated according to the second orthogonal modulation format in the second region of the last one of the symbol blocks; and
of the data symbols including a set of padding symbols and/or bits in a third region of the last symbol block of the symbol blocks and a seventh set of the user bits modulated according to the first orthogonal modulation format. The method further comprising providing a fourth set. 6. The method of claim 5,
outputting the last one of the symbol blocks of the frame for transmission to the remote receiver; and
an eighth of user bits modulated according to the first orthogonal modulation format and a separate symbol pattern identifying the start of the next frame of the symbol blocks in the first region of a first one of the symbol blocks of the next frame and providing a fifth set of data symbols comprising a set. According to claim 1,
providing a third set of data symbols comprising the fifth set of user bits modulated according to the first orthogonal modulation format in a third region of the first one of the symbol blocks; Way. According to claim 1,
selecting the first orthogonal modulation format from a plurality of supported orthogonal modulation formats based on a selected one of a plurality of modes of operation supported by the communication transmitter in response to an operation mode identifier signal; Way. 9. The method of claim 8,
and the distinct symbol pattern includes a predetermined number of symbols corresponding to the selected mode of operation. According to claim 1,
and modulating the frame onto an optical signal to be transmitted to the remote receiver. According to claim 1,
wherein the distinct symbol pattern includes at least one of auto-correlation and cross-correlation characteristics for differential decoding detection by the remote receiver. According to claim 1,
wherein the distinct symbol pattern is modulated according to the second orthogonal modulation format or a third orthogonal modulation format that is different from the second orthogonal modulation format and is a lower modulation order than the first orthogonal modulation format. According to claim 1,
the first set of support symbols consists of the same number of support symbols as the second set of support symbols;
The second region of the first one of the symbol blocks includes the symbol blocks such that the second region of the second one of the symbol blocks is in the second one of the symbol blocks. at the same location of the first symbol block of A system configured to output a frame of symbol blocks each comprising a first region and a second region, the frame being transmitted as a signal to a remote receiver, the system comprising:
a framer input configured to receive user bits; and
A symbol generator comprising:
a data symbol comprising a distinct symbol pattern identifying a start of a frame of said symbol blocks and a first set of user bits modulated according to a first orthogonal modulation format in said first region of a first one of said symbol blocks first set of
a first set of support symbols comprising the second set of user bits modulated according to a second orthogonal modulation format in the second region of the first symbol block of the symbol blocks, wherein the first orthogonal modulation format is higher order than the second orthogonal modulation format -,
a second set of data symbols comprising the third set of user bits modulated according to the first orthogonal modulation format in the first region of a second one of the symbol blocks; and
a second set of support symbols including the fourth set of user bits modulated according to the second orthogonal modulation format in the second region of the second one of the symbol blocks
A system configured to provide 15. The method of claim 14,
The symbol generator generates a third set of data symbols comprising a pattern identifying a middle marker of the frame of the symbol blocks and a fifth set of user bits modulated according to the first orthogonal modulation format into the symbol blocks. and provide the first region of an Xth symbol block of which the Xth symbol block of the symbol blocks corresponds to approximately the middle of the frame. 16. The method of claim 15,
and the symbol generator provides the third set of support symbols including the sixth set of user bits modulated according to the second orthogonal modulation format in the second region of the Xth symbol block of the symbol blocks. further comprising the system. 15. The method of claim 14,
the symbol generator comprises: a third set of data symbols comprising the fifth set of user bits modulated according to the first orthogonal modulation format in the first region of a last one of the symbol blocks of the frame;
a third set of support symbols including the sixth set of user bits modulated according to the second orthogonal modulation format in the second region of the last one of the symbol blocks; and
a fourth set of data symbols and a set of padding symbols including the seventh set of user bits modulated according to the first orthogonal modulation format in a third region of the last symbol block of the symbol blocks; or bits
The system is configured to further provide. 15. The method of claim 14,
the symbol generator is further configured to provide a third set of data symbols comprising the fifth set of user bits modulated according to the first orthogonal modulation format in a third region of the first one of the symbol blocks becoming a system. 15. The method of claim 14,
wherein the symbol generator is further configured to select the first orthogonal modulation format from a plurality of supported modulation formats based on a selected one of a plurality of modes of operation supported by the communication transmitter in response to an operation mode identifier signal. , system. 20. The method of claim 19,
and the distinct symbol pattern includes a predetermined number of symbols corresponding to the selected mode of operation. 15. The method of claim 14,
and an optical modulator configured to modulate the frame onto an optical signal to be transmitted to the remote receiver. 15. The method of claim 14,
and the symbol generator is further configured to generate the distinct symbol pattern having a predetermined set of at least one of auto-correlation and cross-correlation characteristics for differential decoding detection by the remote receiver. 15. The method of claim 14,
wherein the symbol generator is further configured to modulate the distinct symbol pattern according to the second orthogonal modulation format or a third orthogonal modulation format different from the second orthogonal modulation format and a lower modulation order than the first orthogonal modulation format. . 15. The method of claim 14,
the first set of support symbols consists of the same number of support symbols as the second set of support symbols;
The second region of the first one of the symbol blocks includes the symbol blocks such that the second region of the second one of the symbol blocks is in the second one of the symbol blocks. at the same location of the first symbol block of

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